Catalyst compositions having enhanced acidity for dry reforming processes

ABSTRACT

Modified red mud catalyst compositions, methods for production, and methods for use, a composition including red mud material produced from an alumina extraction process from bauxite ore; nickel oxide, the nickel oxide present at between about 5 wt. % to about 40 wt. % of the modified red mud catalyst composition; and a Periodic Table Group VIB metal oxide, the Group VIB metal oxide present at between about 1 wt. % and about 30 wt. % of the modified red mud catalyst composition.

BACKGROUND Field

Embodiments of the disclosure relate to catalyst compositions for use inreforming processes. In particular, certain embodiments of thedisclosure relate to Periodic Table Group VIB metal oxide containingcatalyst compositions for and methods of dry reforming.

Description of the Related Art

Dry reforming simultaneously utilizes two greenhouse gases, CH₄ and CO₂,to produce synthesis (syn) gas (CO and H₂). However, one challenge ofdry reforming is the lack of available, durable, and cost-effectivecatalyst. Dry reforming generally applies a catalyst, increasedtemperature, and increased pressure in a process generally according toEquation 1.

CH₄+CO₂→2H₂+2CO  Eq. 1

Dry reforming generally is not as common as steam reforming, and one useis in processes that require a high proportion of CO versus H₂ in theproduced synthesis gas. The thermodynamics of dry reforming are similarto those of steam reforming. One difference of dry reforming from steamreforming is dry reforming's tendency for coking, increased by a lack ofsteam to remove carbon deposits. In some applications like mixedreforming or bi-reforming (a combination of steam and dry reforming),steam is added for effective reduction or removal of coke. Since cokingcan quickly deactivate Ni catalysts, Rh and Ru catalysts are used insome dry reforming applications.

Present catalyst technology is insufficient in some processes to providecost-effective means for dry reforming.

SUMMARY

Applicant has recognized a need for compositions of Periodic Table GroupVIB (Group VIB) metal oxide containing modified red mud to be applied insystems and processes for dry reforming. Enhanced-acidity Group VIBcatalyst compositions are disclosed, in some embodiments furtherincluding nickel. The enhanced-acidity Group VIB catalysts also containin some embodiments Fe, Al, Si, Na, Ca, and Ti oxides from red mud. Inembodiments of the present disclosure, red mud acts as a catalyst inaddition to or alternative to a catalyst carrier. Disclosed compositionsare useful as a catalyst in dry reforming processes for the conversionof methane to syngas, according to Equation 1. Utilization of red mud indry reforming processes provides the concurrent advantages of utilizinga waste material (red mud), converting CO₂ (a greenhouse gas), andproducing H₂.

Red mud is a caustic waste material produced from bauxite ore processingfor alumina extraction, and is utilized here as a catalyst for a dryreforming process. Surprisingly and unexpectedly, without beingspecifically designed as a catalyst (for example using specific zeoliticstructure), red mud waste material can be readily modified for use as acatalyst. Dry reforming is considered to be a green method for theproduction of syngas (H₂ and CO), since it utilizes as reactants twogreenhouse gases, CH₄ and CO₂. Despite that, widespread adoption of dryreforming processes has been stymied due in part to the lack ofcommercially-available durable and efficient catalysts. Red mudgenerally includes a mixture of transition metals such as Ti, Fe, andAl, which make it an advantageous catalyst for dry reforming processes,for example once modified with nickel and molybdenum.

Embodiments disclosed here apply red mud as an active catalyst support,promotor, in addition to or alternative to catalyst to produce hydrogenthrough dry reforming of methane.

Therefore, disclosed here is a modified red mud catalyst compositionincluding red mud material produced from an alumina extraction processfrom bauxite ore; nickel oxide, the nickel oxide present at betweenabout 5 wt. % to about 40 wt. % of the modified red mud catalystcomposition; and a Periodic Table Group VIB metal oxide, the Group VIBmetal oxide present at between about 1 wt. % and about 30 wt. % of themodified red mud catalyst composition. In some embodiments, the GroupVIB metal oxide comprises at least one metal selected from the groupconsisting of: chromium, molybdenum, and tungsten. In other embodiments,the composition includes at least one component selected from the groupconsisting of: Fe₂O₃, Al₂O₃, SiO₂, Na₂O, CaO, and TiO₂. Still in otherembodiments, a majority of the particles of the composition have aparticle size of less than about 70 In certain other embodiments, thenickel oxide is present at between about 10 wt. % to about 30 wt. % ofthe modified red mud catalyst composition. Still in other embodiments,the nickel oxide is present at between about 15 wt. % to about 25 wt. %of the modified red mud catalyst composition. In some embodiments, thenickel oxide is present at about 23 wt. % of the modified red mudcatalyst composition.

In other embodiments of the composition, the Group VIB metal oxide ispresent at between about 1 wt. % to about 20 wt. % of the modified redmud catalyst composition. In some embodiments, the Group VIB metal oxideis present at between about 1 wt. % to about 10 wt. % of the modifiedred mud catalyst composition. Still in other embodiments, the Group VIBmetal oxide is present at about 5 wt. % of the modified red mud catalystcomposition. In yet other embodiments, the Brunauer-Emmett-Teller (BET)surface area of the modified red mud catalyst composition is betweenabout 50 m²/g and about 90 m²/g.

Additionally disclosed here are methods for producing the modified redmud catalyst compositions, one method including dissolving red mudmaterial produced from an alumina extraction process from bauxite ore inwater to produce a red mud solution; neutralizing the pH of the red mudsolution using an acid; preparing a nickel-containing solution;preparing a Periodic Table Group VIB metal oxide-containing solution;mixing the red mud solution, the nickel-containing solution, and theGroup VIB metal oxide-containing solution to precipitate the modifiedred mud catalyst composition; and calcining the modified red mudcatalyst composition. In some embodiments, the Group VIB metal oxidecomprises at least one metal selected from the group consisting of:chromium, molybdenum, and tungsten. Still in other embodiments, thewater comprises deionized water. In certain embodiments, the acidcomprises hydrochloric acid.

In some other embodiments of the methods, the nickel-containing solutioncomprises nickel nitrate dissolved in ethanol. Still in otherembodiments, the Group VIB metal oxide-containing solution comprisesammonium molybdate dissolved in ethanol. In yet other embodiments, themethod includes filtering the modified red mud catalyst composition anddrying the modified red mud catalyst composition before the step ofcalcining. In some embodiments, the step of drying occurs at about 100°C. Still in other embodiments, the step of calcining takes place forabout 4 hours at between about 500° C. to about 700° C. In yet otherembodiments, the step of calcining takes place for about 4 hours atabout 600° C. Still in yet other embodiments, the method includes thestep of grinding the modified red mud catalyst composition to a particlesize of less than about 70 μm. In some embodiments, the BET surface areaof the modified red mud catalyst composition is between about 50 m²/gand about 90 m²/g.

Additionally disclosed here is a method for dry reforming over amodified red mud catalyst composition, the method including providing amethane feed and carbon dioxide feed to react over the modified red mudcatalyst composition at increased temperature and increased pressure toproduce synthesis gas comprising H₂ and CO, the composition comprising:red mud material produced from an alumina extraction process frombauxite ore; nickel oxide, the nickel oxide present at between about 5wt. % to about 40 wt. % of the modified red mud catalyst composition;and a Periodic Table Group VIB metal oxide, the Group VIB metal oxidepresent at between about 1 wt. % and about 30 wt. % of the modified redmud catalyst composition.

In some embodiments, the Group VIB metal oxide comprises at least onemetal selected from the group consisting of: chromium, molybdenum, andtungsten. Still in other embodiments, the increased temperature isbetween about 500° C. to about 1000° C. In some embodiments, theincreased temperature is between about 600° C. to about 800° C. In otherembodiments, the increased temperature is about 750° C. In certainembodiments, the increased pressure is between about 5 bar and about 20bar. In other embodiments, the increased pressure is between about 10bar and about 15 bar. Still in other embodiments, the increased pressureis about 14 bar. In yet other embodiments, the methane conversion rateis at least about 14% for at least about 6 hours. In yet otherembodiments, gas hourly space velocity of the methane feed and carbondioxide feed mixed is between about 1000 h⁻¹ to 10000 h⁻¹. Still inother embodiments, the composition includes at least one componentselected from the group consisting of: Fe₂O₃, Al₂O₃, SiO₂, Na₂O, CaO,and TiO₂. In certain embodiments, a majority of the particles of thecomposition have a particle size of less than about 70 μm. And in otherembodiments, the nickel oxide is present at between about 10 wt. % toabout 30 wt. % of the modified red mud catalyst composition.

Still in other embodiments, the nickel oxide is present at between about15 wt. % to about 25 wt. % of the modified red mud catalyst composition.In certain embodiments, the nickel oxide is present at about 23 wt. % ofthe modified red mud catalyst composition. In some embodiments, theGroup VIB metal oxide is present at between about 1 wt. % to about 20wt. % of the modified red mud catalyst composition. Still in otherembodiments, the Group VIB metal oxide is present at between about 1 wt.% to about 10 wt. % of the modified red mud catalyst composition. Incertain embodiments, the Group VIB metal oxide is present at about 5 wt.% of the modified red mud catalyst composition. In certain otherembodiments, a molar ratio of the methane feed to the carbon dioxidefeed is between about 1:1 and about 1:1.75. In some embodiments,produced H₂ is at least about 9 mol. % of produced products from thereaction. And in other embodiments, the BET surface area of the modifiedred mud catalyst composition is between about 50 m²/g and about 90 m²/g.

In some embodiments of the compositions and methods described, modifiedred mud catalyst compositions with nickel in addition to or alternativeto molybdenum or other metals include between about 15 wt. % and about30 wt. % Al₂O₃, between about 1 wt. % and about 5 wt. % CaO, betweenabout 10 wt. % and about 30 wt. % Fe₂O₃, between about 1 wt. % and about5 wt. % Na₂O, between about 10 wt. % and about 25 wt. % SiO₂, andbetween about 1 wt. % and about 10 wt. % TiO₂.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure will become better understood with regard to the followingdescriptions, claims, and accompanying drawings. It is to be noted,however, that the drawings illustrate only several embodiments of thedisclosure and are therefore not to be considered limiting of thedisclosure's scope as it can admit to other equally effectiveembodiments.

FIG. 1 is a graph showing conversion percentage for CH₄ in a dryreforming process for unmodified red mud (RM) used as a catalyst and foracid nickel-molybdenum-modified red mud (ANMoMRM) used as a catalyst.

FIG. 2 is a graph showing mol. % of H₂ out of the total productsproduced from dry reforming of CH₄ in a dry reforming process forunmodified red mud used as a catalyst and for ANMoMRM used as acatalyst.

DETAILED DESCRIPTION

So that the manner in which the features and advantages of theembodiments of compositions of Group VIB metal modified red mud, in someembodiments including nickel, along with systems and methods for dryreforming with such compositions and for producing such compositions,may be understood in more detail, a more particular description of theembodiments of the present disclosure briefly summarized previously maybe had by reference to the embodiments thereof, which are illustrated inthe appended drawings, which form a part of this specification. It is tobe noted, however, that the drawings illustrate only various embodimentsof the disclosure and are therefore not to be considered limiting of thepresent disclosure's scope, as it may include other effectiveembodiments as well.

As noted, red mud is a caustic waste material generated during aluminaextraction from bauxite ore. Red mud includes a mixture of transitionmetals, for example as listed in Table 1.

TABLE 1 Example composition ranges for global red mud. Component Fe₂O₃Al₂O₃ SiO₂ Na₂O CaO TiO₂ Approx. 30-60% 10-20% 3-50% 2-10% 2-8% 10%Weight Percentage

Red mud was modified with nickel and molybdenum to be utilized andtested as a catalyst for dry reforming as follows. In some embodiments,nickel is not required. In some embodiments, nickel in addition to oralternative to any one of or any combination of chromium, molybdenum,and tungsten can be used to modify red mud. Saudi Arabian red mud fromMa'aden Aluminium Company, based at Ras Al Khair, Saudi Arabia was usedto prepare a modified catalyst composition. Table 2 shows the weightpercent for certain components in the unmodified Saudi Arabian red mudcomposition.

TABLE 2 Certain component weight percentages in Saudi Arabian red mud(RM) catalyst/catalyst support composition. Component Fe₂O₃ Al₂O₃ SiO₂Na₂O CaO TiO₂ Weight 18.75% 25.22% 18.88% 11.77% 7.97% 6.89% Percentage

The untreated red mud exhibited a Brunauer-Emmett-Teller (BET) surfacearea of about 16 m²/g.

Table 3 shows an example composition for one embodiment of producednickel-molybdenum acid treated red mud for use as a modified catalyst.The unmodified red mud used as a catalyst precursor contained nodetectable nickel or molybdenum.

TABLE 3 Example composition for a produced ANMoMRM used as a catalyst.Component Fe₂O₃ Al₂O₃ SiO₂ Na₂O CaO TiO₂ NiO MoO Weight 16.76% 21.43%19.56% 2.81% 2.76% 5.36% 23.7% 5.06% Percentage

Because red mud is a highly variable waste material, elementalcomposition will vary between samples and test results.

Catalyst Preparation. An acid nickel-molybdenum-modified red mud(ANMoMRM) catalyst with 23.7 wt. % nickel oxide and 5.06 wt. %molybdenum oxide was prepared using a homogeneous precipitation process.Using an unmodified red mud catalyst precursor, 20 wt. % of nickel oxide(also referred to as NiO) was targeted to be loaded in the red mud toenhance dry reforming activity, and 23.7 wt. % of nickel oxide wasconfirmed by X-ray fluorescence (XRF) analysis. Using the unmodified redmud catalyst precursor, 5 wt. % of molybdenum oxide (also referred to asMoO) was targeted to be loaded in the red mud to enhance dry reformingactivity, and 5.06 wt. % of molybdenum oxide was confirmed by XRFanalysis. Depending on the catalyst application, nickel oxide can beloaded to a red mud precursor from between about 1 wt. % to about 50 wt.%, and molybdenum oxide, in addition to or alternative to other GroupVIB metals, can be loaded to a red mud precursor from between about 1wt. % to about 50 wt. %.

First, 10 g of Saudi Arabian red mud from Ma'aden Aluminium Company,based at Ras Al Khair, Saudi Arabia was modified by dissolving dried,unmodified red mud in 100 mL of deionized water, and then the pH wasneutralized using 40.5 mL of 37 wt. % hydrochloric acid. Afterward, 10 gof nickel(II) nitrate hexahydrate was dissolved in 50 mL of ethanol.Then, 0.92 grams of ammonium molybdate tetrahydrate was dissolved in 50mL of ethanol. The three separate solutions were mixed to form a mixedsolution. Next, the mixed solution was filtered, filtered solids weredried in an oven at 105° C., and then calcined at 600° C. for 4 hours.The final ANMoMRM solid product was ground to have a particle size ofless than about 70 The step of drying in an oven can last from about 2to about 24 hours.

Other nickel-containing compounds and molybdenum-containing compoundscan be used in addition to or alternative to nickel nitrate and ammoniummolybdate, including any nickel-containing compounds ormolybdenum-containing compounds soluble in ethanol or other organic orinorganic alcohols, or in aqueous ammonia. XRF in embodiments of thepresent disclosure confirmed the presence of nickel and molybdenum oxideloading in the ANMoMRM. Nickel can be combined with red mud to result innickel(II) oxide, NiO, in addition to or alternative to nickel(III)oxide, Ni₂O₃. Molybdenum can be combined with red mud to result in(molybdenum dioxide, MoO₂) or Molybdenum(VI) oxide (molybdenum trioxide,MoO₃).

BET surface area analysis showed unmodified red mud surface area wasabout 16 m²/g. BET surface area for acid modified red mud was about 170m²/g. BET surface area for acid modified red mud with nickel in additionto or alternative to molybdenum loading is, in some embodiments, betweenabout 50 m²/g and about 90 m²/g, for example about 63 m²/g or about 89m²/g.

Catalyst testing. Several tests on red mud catalytic activity andANMoMRM catalytic activity for dry reforming were experimentallyconducted. Saudi Arabian red mud was tested as received as a catalystsupport without any modifications, and it was placed in an AvantiumFlowrence® catalyst testing reactor to perform dry reformingexperiments. The Avantium Flowrence® reactor is a flexible,high-throughput catalyst testing system that was operated using about0.5 g of catalyst samples. The ANMoMRM catalyst was tested in aMicromeritics® PID Eng & Tech brand microactivity reactor designed forcatalyst activity and selectivity analysis. The results are compared,for example, in FIGS. 1 and 2. Results show that ANMoMRM catalyticactivity for dry reforming is advantageously improved over non-modifiedred mud catalytic activity for dry reforming.

FIG. 1 is a graph showing conversion percentage for CH₄ in a dryreforming process for unmodified red mud used as a catalyst and forANMoMRM used as a catalyst. Effects of nickel and molybdenum addition tored mud were studied. Experimental conditions in the dry reformingreactor included temperature at about 750° C., pressure at about 14 bar,and gas hourly space velocity (GHSV) at about 1477 h⁻¹. The test wasconducted for 6 hours. Catalysts tolerant at high pressure are favoredfor dry reforming processes. The feed was 50 mol. % methane and 50 mol.% CO₂ for both catalysts tested. The GHSV was calculated for the mixedfeed. GHSV generally measures the flow rate of the feed gases divided bythe catalyst volume, which indicates the residence time of the reactantson the catalyst.

For dry reforming, the feed composition will include CH₄ and CO₂. Insome embodiments for dry reforming, a feed will consist essentially ofor consist of CH₄ and CO₂. Based on thermodynamics, the molar ratio ofthe feed for CH₄ to CO₂ can be about 1:1. However, some otherembodiments showed that greater CO₂ concentrations up to 1:1.75 (moleCH₄ to mole CO₂) surprisingly and unexpectedly enhanced H₂ production.

Methane conversion illustrated in FIG. 1 shows ANMoMRM catalystoutperformed its counterpart, the untreated red mud. Methane conversionby ANMoMRM reached up to about 17%, and remained nearly constant at thislevel during the experiment's duration. On the other hand, unmodifiedred mud methane conversion maxed out at about 14%, then deteriorated.Slight conversion activity of unmodified red mud could be attributed tothe existence of several transition metals within red mud, and thegreater conversion rate of ANMoMRM can be attributed to the addition ofnickel and molybdenum, and synergies of the nickel and molybdenum withthe existing transition metals in the red mud.

FIG. 2 is a graph showing mol. % of H₂ out of the total productsproduced from dry reforming of CH₄ in a dry reforming process forunmodified red mud (RM) used as a catalyst and for ANMoMRM used as acatalyst. Hydrogen production illustrated in FIG. 2 shows that untreatedred mud produced low amounts of hydrogen, whereas ANMoMRM catalystproduced up to about 11 mol. % hydrogen. Nickel-molybdenum modificationof red mud has enhanced the performance significantly for hydrogenproduction.

The singular forms “a,” “an,” and “the” include plural referents, unlessthe context clearly dictates otherwise. The term “about” when used withrespect to a value or range refers to values including plus and minus 5%of the given value or range.

In the drawings and specification, there have been disclosed exampleembodiments of the present disclosure, and although specific terms areemployed, the terms are used in a descriptive sense only and not forpurposes of limitation. The embodiments of the present disclosure havebeen described in considerable detail with specific reference to theseillustrated embodiments. It will be apparent, however, that variousmodifications and changes can be made within the spirit and scope of thedisclosure as described in the foregoing specification, and suchmodifications and changes are to be considered equivalents and part ofthis disclosure.

That claimed is:
 1. A modified red mud catalyst composition, thecomposition comprising: red mud material produced from an aluminaextraction process from bauxite ore; nickel oxide, the nickel oxidepresent at between about 5 wt. % to about 40 wt. % of the modified redmud catalyst composition; and a Periodic Table Group VIB metal oxide,the Group VIB metal oxide present at between about 1 wt. % and about 30wt. % of the modified red mud catalyst composition.
 2. The compositionaccording to claim 1, where the Group VIB metal oxide comprises at leastone metal selected from the group consisting of: chromium, molybdenum,and tungsten.
 3. The composition according to claim 1, furthercomprising at least one component selected from the group consisting of:Fe₂O₃, Al₂O₃, SiO₂, Na₂O, CaO, and TiO₂.
 4. The composition according toclaim 1, where a majority of the particles of the composition have aparticle size of less than about 70 μm.
 5. The composition according toclaim 1, where the nickel oxide is present at between about 10 wt. % toabout 30 wt. % of the modified red mud catalyst composition.
 6. Thecomposition according to claim 1, where the nickel oxide is present atbetween about 15 wt. % to about 25 wt. % of the modified red mudcatalyst composition.
 7. The composition according to claim 1, where thenickel oxide is present at about 23 wt. % of the modified red mudcatalyst composition.
 8. The composition according to claim 1, where theGroup VIB metal oxide is present at between about 1 wt. % to about 20wt. % of the modified red mud catalyst composition.
 9. The compositionaccording to claim 1, where the Group VIB metal oxide is present atbetween about 1 wt. % to about 10 wt. % of the modified red mud catalystcomposition.
 10. The composition according to claim 1, where the GroupVIB metal oxide is present at about 5 wt. % of the modified red mudcatalyst composition.
 11. The composition according to claim 1, wherethe Brunauer-Emmett-Teller (BET) surface area of the modified red mudcatalyst composition is between about 50 m²/g and about 90 m²/g.
 12. Thecomposition according to claim 1, where the composition includes betweenabout 15 wt. % and about 30 wt. % Al₂O₃, between about 1 wt. % and about5 wt. % CaO, between about 10 wt. % and about 30 wt. % Fe₂O₃, betweenabout 1 wt. % and about 5 wt. % Na₂O, between about 10 wt. % and about25 wt. % SiO₂, and between about 1 wt. % and about 10 wt. % TiO₂.
 13. Amethod for producing the modified red mud catalyst composition of claim1, the method comprising the steps of: dissolving red mud materialproduced from an alumina extraction process from bauxite ore in water toproduce a red mud solution; neutralizing the pH of the red mud solutionusing an acid; preparing a nickel-containing solution; preparing aPeriodic Table Group VIB metal oxide-containing solution; mixing the redmud solution, the nickel-containing solution, and the Group VIB metaloxide-containing solution to precipitate the modified red mud catalystcomposition; and calcining the modified red mud catalyst composition.14. The method according to claim 13, where the Group VIB metal oxidecomprises at least one metal selected from the group consisting of:chromium, molybdenum, and tungsten.
 15. The method according to claim13, where the water comprises deionized water.
 16. The method accordingto claim 13, where the acid comprises hydrochloric acid.
 17. The methodaccording to claim 13, where the nickel-containing solution comprisesnickel nitrate dissolved in ethanol.
 18. The method according to claim13, where the Group VIB metal oxide-containing solution comprisesammonium molybdate dissolved in ethanol.
 19. The method according toclaim 13, further comprising filtering the modified red mud catalystcomposition and drying the modified red mud catalyst composition beforethe step of calcining.
 20. The method according to claim 19, where thestep of drying occurs at about 100° C.
 21. The method according to claim13, where the step of calcining takes place for about 4 hours at betweenabout 500° C. to about 700° C.
 22. The method according to claim 13,where the step of calcining takes place for about 4 hours at about 600°C.
 23. The method according to claim 13, further comprising the step ofgrinding the modified red mud catalyst composition to a particle size ofless than about 70 μm.
 24. The method according to claim 13, where theBrunauer-Emmett-Teller (BET) surface area of the modified red mudcatalyst composition is between about 50 m²/g and about 90 m²/g.
 25. Themethod according to claim 13, where the composition includes betweenabout 15 wt. % and about 30 wt. % Al₂O₃, between about 1 wt. % and about5 wt. % CaO, between about 10 wt. % and about 30 wt. % Fe₂O₃, betweenabout 1 wt. % and about 5 wt. % Na₂O, between about 10 wt. % and about25 wt. % SiO₂, and between about 1 wt. % and about 10 wt. % TiO₂.
 26. Amethod for dry reforming over a modified red mud catalyst composition,the method comprising the steps of: providing a methane feed and carbondioxide feed to react over the modified red mud catalyst composition atincreased temperature and increased pressure to produce synthesis gascomprising H₂ and CO, the composition comprising: red mud materialproduced from an alumina extraction process from bauxite ore; nickeloxide, the nickel oxide present at between about 5 wt. % to about 40 wt.% of the modified red mud catalyst composition; and a Periodic TableGroup VIB metal oxide, the Group VIB metal oxide present at betweenabout 1 wt. % and about 30 wt. % of the modified red mud catalystcomposition.
 27. The method according to claim 26, where the Group VIBmetal oxide comprises at least one metal selected from the groupconsisting of: chromium, molybdenum, and tungsten.
 28. The methodaccording to claim 26, where the increased temperature is between about500° C. to about 1000° C.
 29. The method according to claim 26, wherethe increased temperature is between about 600° C. to about 800° C. 30.The method according to claim 26, where the increased temperature isabout 750° C.
 31. The method according to claim 26, where the increasedpressure is between about 5 bar and about 20 bar.
 32. The methodaccording to claim 26, where the increased pressure is between about 10bar and about 15 bar.
 33. The method according to claim 26, where theincreased pressure is about 14 bar.
 34. The method according to claim26, where the methane conversion rate is at least about 14% for at leastabout 6 hours.
 35. The method according to claim 26, where gas hourlyspace velocity of the methane feed and carbon dioxide feed mixed isbetween about 1000 h⁻¹ to 10000 h⁻¹.
 36. The method according to claim26, where the composition includes at least one component selected fromthe group consisting of: Fe₂O₃, Al₂O₃, SiO₂, Na₂O, CaO, and TiO₂. 37.The method according to claim 26, where a majority of the particles ofthe composition have a particle size of less than about 70 nm.
 38. Themethod according to claim 26, where the nickel oxide is present atbetween about 10 wt. % to about 30 wt. % of the modified red mudcatalyst composition.
 39. The method according to claim 26, where thenickel oxide is present at between about 15 wt. % to about 25 wt. % ofthe modified red mud catalyst composition.
 40. The method according toclaim 26, where the nickel oxide is present at about 23 wt. % of themodified red mud catalyst composition.
 41. The method according to claim26, where the Group VIB metal oxide is present at between about 1 wt. %to about 20 wt. % of the modified red mud catalyst composition.
 42. Themethod according to claim 26, where the Group VIB metal oxide is presentat between about 1 wt. % to about 10 wt. % of the modified red mudcatalyst composition.
 43. The method according to claim 26, where theGroup VIB metal oxide is present at about 5 wt. % of the modified redmud catalyst composition.
 44. The method according to claim 26, where amolar ratio of the methane feed to the carbon dioxide feed is betweenabout 1:1 and about 1:1.75.
 45. The method according to claim 26, whereproduced H₂ is at least about 9 mol. % of produced products from thereaction.
 46. The method according to claim 26, where theBrunauer-Emmett-Teller (BET) surface area of the modified red mudcatalyst composition is between about 50 m²/g and about 90 m²/g.
 47. Themethod according to claim 26, where the composition includes betweenabout 15 wt. % and about 30 wt. % Al₂O₃, between about 1 wt. % and about5 wt. % CaO, between about 10 wt. % and about 30 wt. % Fe₂O₃, betweenabout 1 wt. % and about 5 wt. % Na₂O, between about 10 wt. % and about25 wt. % SiO₂, and between about 1 wt. % and about 10 wt. % TiO₂.